Sb–Te layers having various compositions between Sb 2 Te 3 and Sb 2 Te are grown using molecular beam epitaxy. The structural and electrical properties of the layers change gradually with composition but exhibit a discontinuity involving a bistability. The holes in the layers are generated by Sb bilayers intercalated between Sb 2 Te 3 quintuple layers and their mobility is governed by the scattering from the parent acceptors. Magnetoresistance for compositions around SbTe is linear, for which the reduction of the parabolic component due to low mobility is crucial. Density functional calculations predict Sb 2 Te 3 and SbTe to be topological insulators (TIs) resembling Bi 2 Se 3 and Bi 2 Te 3, respectively. The prefactor of the weak antilocalization effect is α=− 1 regardless of the composition. The Sb–Te system is thus a family of TIs possessing undisturbed surface states for which the location of the Dirac point with …